This week on HANDMADE.hackaday we’ve seen a pretty good variety of skills.
HANDMADE.hackaday.com is growing quickly. Keep sending in those good tips! We have some videos of our own planned as well, keep an eye out for those!
[José Manuel Hermo Barreiro] has spent many many hours crafting these tiny engines from hand. Every single piece is custom made specifically for the engine it is going onto. He has created aircraft engines, car engines, and marine engines that all actually run and are the smallest of their kind in the world.
At one point in this video he stands in a room with several engines lined up, all running smoothly and considers that there are possibly over 15,000 hours of work right there in front of him.
Here’s a video specifically about the 12 cylinder construction.
[Thanks Staskazz]
[Kripthor] suspected that hunters were getting too near his house. When thinking of a way to quantify this belief he set out to build a triangulation system based on the sound of gunshots. The theory behind it is acoustic location, which is a specialized type echolocation.
The most common example of echolocation is in Bats, who emit ultrasonic noise and listen for its return (echo) to judge the location of objects. [Kripthor] doesn’t need to generate the sound himself, he just needs to pick it up at different points. The time difference from the three samples can be used to triangulate coordinates as seen in the image above.
He first tried using a PC sound card to collect the samples. The stereo input only provides two channels so he tinkered around with a 555-based multiplexing circuit to sample from three. The circuit noise created was just too great so he transitioned to using an Arduino. The ADC samples from each microphone via an NPN transistor which is used as a simple amplifier.
This brings to mind a homebrew sonar hack from way back.
Last week we caught wind of a piece from the Today Show that shows very technically minded thieves stealing cars with a small device. Cops don’t know how they’re doing it, and of course the Today show (and the Hackaday comments) were full of speculation. The top three theories for how these thieves are unlocking car doors are jamming a keyless entry’s ‘lock signal’, a radio transmitter to send an ‘unlock’ code, or a small EMP device touched to the passenger side door to make it unlock.
That last theory – using a small EMP device to unlock a car’s door – got the attention of someone who builds mini EMP devices and has used them to get credits on slot machines. He emailed us under a condition of anonymity, but he says it’s highly unlikely a mini EMP device would be able to activate the solenoid on a car door.
This anonymous electromagnetic wizard would like to open up a challenge to Hackaday readers, though: demonstrate a miniature EMP device able to unlock an unmodified car door, and you’ll earn the respect of high voltage tinkerers the world over. If you’re successful you could always sell your device to a few criminal interests, but let’s keep things above board here.
Machinist, electronics engineer, programmer, and factory worker are all skills you can wield if you take on a project like building this omniwheel robot (translated).
The omniwheels work in this tripod orientation because they include rollers which turn perpendicular to the wheel’s axis. This avoids the differential issue cause by fixed-position wheels. When the three motors are driven correctly, as shown in the video below, this design makes for the most maneuverable of wheeled robots.
An aluminum plate serves as the chassis. [Malte] milled the plate, cutting out slots for the motor with threaded holes to receive the mounting screws. A few stand-offs hold the hunk of protoboard which makes up the electronic side of the build. The large DIP chip is an ATmega168. It drives the motors via the trio of red stepper motor driver boards which he picked up on eBay.
So far the vehicle is tethered, using a knock-off of a SixAxis style controller. But as we said before, driving the motors correctly is the hard part and he’s definitely solved that problem.
Continue reading “Omniwheel Robot Build Uses A Bit Of Everything”
In the title of his post [Donald Derek] calls this a Google TV you can build yourself. That’s certainly an over-reach. But the project is still a very impressive smart television built using a Raspberry Pi.
The open source project starts with the Rasbian OS, an RPi version of Debian Linux. Functionality is built up by installing Chromium to display webpages, a script to download YouTube videos, and OMXPlayer to play videos including 1080P HD content. The image above shows the smart phone controller for the system. This is provided by a Node.js configuration that manages communication between the remote and the RPi board.
On the one hand we love that this is open source. On the other, it’s not going to be able to tap into a lot of the content which makes a Google TV so valuable. For instance, you won’t be able to watch Netflix because that service doesn’t work on Linux systems. But you should be able to watch browser-based content like Hulu.
One of the marks of how busy you are – or how well your spam filters are set up – is how many unread emails you have in your inbox. [trumpkin] over on Instructables posted a great tutorial for making a wireless counter that displays the number of unread emails in your Gmail account.
[trumpkin] used a tiny and inexpensive 419 MHz transmitter and receiver combo to make this project work. On his desktop, he wired up a USB to UART bridge attached to the transmitter. For the receiver side, an ATMega328 reads the data coming off the receiver and displays the number of unread emails on two seven-segment displays.
The wireless device runs off of two AA batteries and should provide enough power to keep the email monitor running for a long time. More than enough time for your inbox to fill up and for you to become overwhelmed with the work you should be doing.
